Islamabad: The United States embassy in Islamabad on Sunday prohibited its staff from visiting the federal capital's Marriott Hotel, citing concerns of a "possible attack".

"Event: U.S. government staff prohibited from visiting Islamabad's Marriott Hotel du a security alert issued today, the US embassy asked its government staff to exercise vigilance at places of worship, and avoid locations with large crowds. It also asked them to monitor local media for updates.e to possible attack," the US embassy in Islamabad said in an alert posted on its website.

This security alert comes two days after a suicide bombing in the capital killed a policeman and wounded six others, the Dawn newspaper reported. In its security alert, the US embassy said it was "aware of information that unknown individuals are possibly plotting to attack Americans at the Marriott Hotel in Islamabad sometime during the holidays".

"Effective immediately, the Embassy in Islamabad is prohibiting all American staff from visiting Islamabad's Marriott Hotel," the alert said.

As Islamabad was placed on red alert citing security concerns while banning all public gatherings, the embassy urged all Mission personnel to refrain from non-essential, unofficial travel to Islamabad throughout the holiday season.

On Friday, the administration in the Capital banned all types of gatherings, especially activities related to the upcoming local government elections, and declared high alert in the city.

"In light of recent advisories/threat alerts issued by the law enforcement agencies and today's attack on police, the security of Islamabad has been beefed up to obviate the threats within the jurisdiction of capital which can disrupt peace and tranquility causing damage to public life and property," read a notification issued by the office of Deputy Commissioner Irfan Nawaz Memon, as quoted by Dawn.

Police imposed a ban on all kinds of corner meetings, public gatherings and congregations, especially in the wake of the upcoming local government elections, the report added.

The Pakistani publication said the order immediately came into force and shall remain in force for two weeks.